USED car values in May fell year-on-year by 4.6%, according to CAP Motor Research's car price index based on a basket of more than 100 vehicles at three years/45,000 miles.

This was down on April's 4.2% decline but CAP says that, while the figures paint a continuing depression in the used car market, they are distorted this year by the new plate system. A large number of cars returned to the market as part-exchanges in March - along with leasing, contract hire and rental company disposals - which led to an imbalance of supply and demand not seen previously at this time of year.

Consequently, says CAP, the impact was not felt until about a month later when jittery nerves in the trade led to lower prices being offered. The month-by-month rate of decline has increased from 0.4% in April to 1.7% in May but CAP chief economist Mark Cowling says: 'The market may not look well but a 1% fall is not outside the magnitude of a normal seasonal drop: it's just that this is the first seasonal drop of its kind we have seen. We expect a continuing mixture of good and bad news as our figures reveal a market which is bumping along the bottom rather than worsening.'